Cylinder head for internal combustion engine



Ap il 16, 1968 J. J. KOTLlN ETAL 3,377,996

CYLINDER HEAD FOR INTERNAL COMBUSTION ENGINE 2 Sheets-Sheet 1 Filed Dec. l0, 1965 M y M J //V4W 1 w v| W .W A i A 1 w W //V r! W 5 7 w v w W fin "W 7 I 7. 7% W p 2 4. AA/ w, W m C. VM V/H April 6, 1968 J. J. KOTLIN ETAL 3,377,996

CYLINDER HEAD FOR INTERNAL COMBUSTION ENGINE 2 Sheets-Sheet f1 Filed Dec. 10, 1965 13am m A/QSQ [M ATTORNEY United States Patent 3,377,996 CYLTNDER l-IEAB FGR INTERNAL CGMEUSTIQN ENGINE .larnes .l. Kotlin, Downers Grove, Donald L. Anderson, L ons, and Bernard Ristig, La Grange, Ill., assignors to General Motors Corporation, Detroit, Mich, a corporation of Delaware Filed Dec. 19, 1965, Ser. No. 513,629 8 Claims. (Cl. 12341.31)

ABSTRACT OF THE DISCLOSURE An internal combustion engine cylinder head includes upper and lower water jacket portions with a plurality of equiangularly spaced exhaust passages extending through the lower jacket portion. Radial webs connect the walls of each passage with the lower jacket periphery to divide the lower jacket into sections. Coolant inlet and outlet openings are provided in alternate jacket sections near the periphery of the jacket such that coolant enters the lower jacket near the periphery of alternate sections and sweeps around the entire circumference of the exhaust passage before leaving the lower jacket through openings adjacent the periphery of the remaining alternate sections. An injector mounting boss, located centrally of the exhaust passages is also cooled by the high velocity flow of coolant. Cooling spines along the lower jacket wall increase the cooling effect adjacent the combustion chamber.

This invention relates to internal combustion engines and, more particularly, to cylinder structure for such engines and with regard to certain more specific aspects thereof to a cylinder head for a valvedn-head uniflow scavenged fuel injection engine of the compression ignition type.

In its more specific aspects, the present invention relates to a cylinder head construction of the type disclosed in United States Patent No. 3,081,755, Kotlin et al. and constitutes improvements in arrangement of the cooling jacket structure so as to increase cooling efficiency in the heavily thermally loaded areas of the valve seats and injector mounting openings in the firing face of the cylinder head. These improvements are accomplished in part by dividing into sections the lower water jacket of the cylinder head and relating the coolant inlet and outlet openings therefrom such that coolant enters the lower jacket in certain sections of the lower jacket near the periphery of the head and then sweeps around nearly the entire circumference of the valve seats before being permitted to leave the lower jacket from other sections thereof. This arrangement has resulted in increased coolant velocitybetween the valve seats and past the injector mounting wall which has increased cooling efficiency in these areas. In addition, coo-lin g efficiency has been further increased by the application of a plurality of cooling spines to the cooling jacket surface of the combustion chamber wall.

The foregoing changes, as well as others to be hereinafter described, have rendered the cylinder head constructions incorporating them better able to withstand the increased operating temperatures required by higher engine outputs while avoiding failures due to cyclic stressing of the combustion chamber wall as well as other problems mentioned in the aforementioned Kotlin et al. patent.

Further objects and advantages will be apparent from the following description and drawings of a preferred embodiment of the invention in which:

FIGURE 1 is a top elevational view of a cylinder head embodying the invention;

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FIGURES 2 and 3 are vertical sectional views taken substantially in the planes of the lines indicated at 22 and 33 respectively of FIGURE 1;

FIGURE 4 is a vertical sectional view taken substantially in the plane indicated by the line 4-4 of FIG- URE 2; and

FIGURES 5, 6 and 7 are horizontal sectional views taken substantially in the planes indicated by the lines 55, 6-5 and 77 respectively of FIGURE 2.

Referring now to the drawings, numeral 10 indicates a cylinder head of the general type shown in United States Patent No. 3,081,755, Kot'lin et al., but having significant differences in the cooling water jacket structure as will be subsequently more fully described. The cylinder head embodiment disclosed is primarily intended for use in a unitlow scavenged two-cycle engine of the fuel injection compression ignition type and is adapted to be secured in end sealing engagement to the upper end of a jacketed liquid cooled cylinder liner and to be mounted therewith in a cylinder mounting bore of an engine frame member wherein the cylinder head 10 cooperates with a piston reciprocably mounted in the liner to define an expansible combustion chamber therebetween.

The cylinder head ltl comprises a lower combustion chamber defining deck or wall 12 engageable outwardly with the upper end of the associated jacketed liner. An upper deck or wall 14 extends in spaced parallel relation to the lower deck and is connected thereto by a peripheral side wall 16. A flange 13 is coextensive with and extends upwardly and outwardly of the upper wall 14 and the side wall 16 to provide an annular shoulder 20. In mounting the cylinder assembly, this flange defined shoulder of the cylinder head is engageable with a mating shoulder provided therefor in the engine frame.

The side wall 16 and flange 18 are structurally reinforced by a plurality of spaced vertically extending bosses 22, 23, 24, 25, 26, 27, 28 and 29. These bosses define a plurality of bolt holes 30 which are adapted to receive through-bolts for securing the cylinder head to the jacketed cylinder liner. The upper and lower decks are interconnected centrally of the head by a sleeve defining wall portion 32. This sleeve defining wall provides a central opening 33 extending through the cylinder head which is of stepped and tapered diameters and is adapted to mount a suitable fuel injection device.

F our valve seat defining exhaust ports 34 extend through the combustion chamber wall 12 of the head in equispaced relation about the injector mounting opening. These exhaust ports communicate upwardly through short branch passages 35, 36, 37 and 38 with a common exhaust passage or chamber 39. The branch passages are defined by wall portions 41, 42, 43 and 44 which extend upwardly between the combustion chamber wall 12 and a horizontal partition Wall 45. This partition wall extends inwardly from the side wall 16 in spaced parallel relation above the combustion chamber wall 12 and terminates inwardly at its intersection with the injector mounting tube or wall 32. Four webs or vertical partition walls 46 are provided extending vertically between the lower wall 12 and partition wall 45 and laterally between each of the passage defining walls 41, 42, 43, 44 and the adjacent bosses 23, 24, 27 and 28 respectively which connect with side wall 16.

The exhaust passage 39 is defined between the partition wall 45 and an upper passage defining wall 47. This upper passage wall is structurally connected to the upper head wall 14 by four tubular or cylindrical wall portions 48 which extend therebetween in axial alignment with the several valve seating ports 34 and define bores 49 adapted to receive suitable valve guide bushings.

As best seen in FIGURE 5, the exhaust passage 39 extends arcuately of the head, partially embracing the injector mounting sleeve in spaced relation thereto and intersecting the several valve controllable branch passages 38, and communicates laterally outwardly with an exhaust outlet port opening through the side wall 16 of the head. This outlet port is connectible to an exhaust manifold through a suitable branch passage which may be provided in the engine frame. The port opening is vertically intersected by two struts 51 and 52. These struts are co-extensive with the bolt hold defining bosses 22 and 29 respectively and each has a passage 54 extending therethrough. The passages 54 permit the circulation of a cooling fluid through the gas exposed struts 51 and 52.

It will be seen that the partition and exhaust passage defining walls cooperate with the outer walls of the head to define a coolant-receiving compartment. This compartment is divided by the horizontal partition wall 45 into a lower jacket chamber and an upper jacket chamber 56. The lower chamber 55 is divided by webs 46 into four sections 58, 59, and 61 which are interconnected by restricted passages 62 formed between exhaust passage defining wall portions 41, 42, 43 and 44 and the injector mounting sleeve 32.

The upper and lower jacket chambers are interconnected through various openings in partition wall 45 adjacent the inner periphery of side wall 16. The primary connection is through a pair of relatively large passages 64 extending from sections 58 and 60 of the lower chamber upwardly past the upper exhaust passage wall 47 to the upper chamber. The chambers are also connected through four small openings connecting with section 59 and passages 54 and in struts 51 and 52 which connect with section 61 of the lower chamber.

The cooling fluid is forced or drawn upwardly into the cylinder head through twelve ports extending through and spaced around the lower head wall 12 adjacent side wall 16. For reasons which will subsequently be made apparent, eight of these are relatively large ports 66 which open into sections 59 and 61 of the lower chamber while four are relatively small ports 68 opening into sections 58 and 60 of the lower chamber. The ports 66 and 68 mate with corresponding ports provided in the jacketed cylinder liner structure which is connected in a conventional manner to the discharge of a coolant circulating pump. As shown in FIGURE 1, the upper flange portion 18 has an outlet passage 69 opening inwardly on the upper chamber 56 and outwardly on a machined face 70 thereof. This outlet passage is connectable through a suitable fitting with a Water outlet manifold to the inlet of the coolant circulating pump in a conventional manner so that forced circulation of coolant through the cylinder head may be provided.

In order to increase cooling efficiency in the critical combustion surface areas of the lower head wall, a plurality of cooling splines 71 are disposed on the inner surface of the lower wall which are distributed among the four sections of the lower chamber over surface area located between the exhaust branch passages 3538 and extending radially outwardly thereof. Additional web members are provided in the lower chamber for supporting the partition wall 45 and assisting in directing coolant flow, including a pair of radially directed members 72 disposed in sections 58 and 60 and a radially directed member 74 in chamber 61 which intersects wall 16 and includes an opening 75 for permitting the equalization of cool-ant flow. Also included is a radial member 76 extending from a diagonal boss 78 which is located in chamber 59 and encloses a cylinder test passage 79.

A primary reason for the eflicient cooling of the critical valve seat and injector opening areas in the herein-disclosed cylinder head embodiment is the velocity and path of coolant flow through the head and, particularly, in the lower coolant chamben, By far, the major portion of coolant flow enters the cylinder head through openings 66 in sections 59 and 61 of the lower chamber. The closely spaced partition wall 45 directs the coolant inwardly to ward the center of the head and it sweeps completely around the peripheries of exhaust passage wall portions 41-44, passes into sections 58 and 6t and out of the lower chamber through passages 64 leading to the upper chamber. The velocity of the coolant is accelerated due to the constricted passages between the exhaust branch passage walls 41-44 as well as between the injector tube wall 32 and the various branch passage walls. The cooling splines, located between the branch passage walls, further accelerate the flow and increase turbulence to obtain a high degree of scrubbing action and very efficient cooling. The small inlet openings 68, provided in sections 58 and 60, pass a very small percentage of coolant flow into the" head and serve to prevent the existence of hot spots due to stagnation of the coolant at the perimeter of these sections.

Upon passing upwardly through passages 64 into the upper chamber, the coolant sweeps over the exhaust passage defining wall 47 and around the outer peripheries of injector tube 32 and valve guide wall portions 48 before leaving the upper chamber through outlet passage 69. In order to prevent stagnation at the edges of the upper chamber, a restricted flow of coolant is permitted to pass directly from chamber 59 through small openings 55 in partition wall 45 and into the upper chamber. Likewise, a small flow of coolant is permitted to pass from section 66 of the lower chamber through restrictive openings 80 in passages 54 to cool the struts 51 and 52 as well as prevent stagnation in the upper chamber.

As previously mentioned, the largest portion of the coolant enters the head through openings 66, sweeps around the peripheries of the exhaust passage walls and up through passages 64 to the upper coolant chamber of the cylinder head resulting in a high velocity turbulent scrubbing action in the vicinity of the valve seat openings and the injector opening and giving a highly eflicient cooling action. In addition, this section has been shown to substantially reduce scale formation in the interior of the cylinder head. This is advantageous since scale acts as an insulator, preventing the coolant from adequately removing heat from the cylinder head surfaces and sometimes causing premature failures.

While the foregoing description of the invention has been limited to a single illust:ative embodiment, it is apparent that various modifications and changes could be made therein without departing from the spirit and scope of the invention as defined by the following claims.

We claim:

1; A cylinder head for an internal combustion engine, said cylinder head defining a coolant receiving jacket and comprising a combustion chamber defining wall,

a cylindrical wall portion adapted to mount a fuel.

injector extending through said jacket compartment and opening through said combustion chamber defining wall,

exhaust passage defining walls extending through Said jacket compartment and spacedly embracing a portion of said injector mounting wall portion, said passage defining walls terminating in an even number of valve controllable ports opening through the surface of said combustion chamber defining wall in equispaced relation to each other and to the injector mounting opening,

a partition wall extending transversely through said coolant jacket in closely spaced parallel relation to said combustion chamber defining wall and dividing said jacket compartment into a flow restricting lower jacket chamber and a relatively unrestricted upper jacket chamber, said partition wall connecting with said injector mounting wall and said passage defining walls,

a plurality of partition webs in said lower jacket chamber, one extending outwardly from each of said passage defining walls and dividing said lower jacket chamber into an even number of sections connected by passages between said passage defining walls and said injector mounting wall,

a plurality of primary coolant inlet openings through said combustion chamber defining wall and opening into alternate sections of said lower jacket chamber adjacent the periphery thereof, said openings being connectable to the outlet of coolant circulating means,

primary coolant passage means adjacent the periphery of said jacket compartment and connecting said upper jacket chamber with alternate sections of Said lower jacket chamber other than said first-named alternate sections, and

a coolant outlet port opening to said upper jacket chamber and connectable to the inlet of coolant circulating means whereby a primary coolant flow path is established into the outer edges of alternate sections of said lower jacket chamber, around said valve controllable port defining walls, past said fuel injector mounting wall into alternate sections of said lower jacket chamber other than said first-named alternate sections, up through passages adjacent the outer edges of said last-named alternate sections into said upper jacket compartment and out through said coolant outlet port.

2. A cylinder head as defined in claim 1 and furthe comprising a plurality of cooling spines projecting upwardly from the coolant chamber surface of said combustion chamber defining wall and disposed between adjacent passage defining walls to increase cooling efficiency at said locations.

3. A cylinder head as defined in claim 1 and further comprising a plurality of small secondary coolant passing openings through said partition wall adjacent the periphery of said jacket compartment and connecting said upper jacket chamber with said first-named alternate sections of said lower jacket chamber, said secondary coolant passing openings being adapted to pass a substantially smaller volume of coolant than is passed through said primary coolant passage means.

4. A cylinder head as defined in claim 3 and further comprising a plurality of restricted secondary coolant inlet ports through said combustion chamber defining wall and opening into said last-named alternate sections of said lower jacket chamber adjacent the periphery thereof, said secondary coolant inlet ports being connectable to the outlet of coolant circulating means and being adapted to pass a substantially smaller volume of coolant than that which is passed through said primary coolant inlet openings.

5. In a cylinder head for an internal combustion engine,

a first combustion chamber defining wall,

a second wall closely spaced therefrom and defining a coolant chamber therebetween,

a boundary wall connecting said first and second walls around their edges to enclose said coolant chamber,

at least two passage defining walls each extending between the first and second walls through the coolant chamber and terminating in a port opening through the first wall,

a partition web associated with each said passage defining wall and connecting it with said boundary wall, thereby blocking substantial coolant flow therebetween and dividing said coolant chamber into a number of sections equal to the number of said passage defining walls and interconnected only by passages formed between said passages defining walls, and

primary coolant inlet and outlet means connectable to coolant circulating means and opening to different sections of said coolant chamber on opposite sides of each said partition web whereby a,substantial portion of the coolant flow from said inlet means is directed around the periphery of each said passage defining wall to said outlet means.

6. In a cylinder head for an internal combustion engine,

a first combustion chamber defining wall,

a second wall closely spaced therefrom and defining a coolant chamber therebetween,

a boundary wall connecting said first and second walls around their edges to enclose said coolant chamber,

an even number of passage defining walls, not less than four, etxending between the first and second walls through the coolant chamber and annularly spaced therein, each terminating in a port opening through the first wall,

a partition web associated with each said passage defining wall and connecting it with said boundary wall, thereby blocking substantial coolant flow therebetween and dividing said coolant chamber into a number of sections equal to the number of said passage defining walls and interconnected only by passages formed between said passage defining walls and primary coolant inlet and outlet means connectable to coolant circulating means and opening to different sections of said coolant chamber adjacent its periphery and on opposite sides of each said partition web, said primary coolant inlet means opening to alternate sections of said coolant chamber and said primary coolant outlet means opening to alternate sections of said coolant chamber other than said first named alternate sections, whereby a substantial portion of coolant flow from said inlet means is directed around the periphery of each said passage defining wall to said outlet means.

7. In the cylinder head of claim 6, a component receiving wall disposed centrally of said passage defining walls and extending between said first and second walls through the coolant chamber, said component receiving wall terminating in a port opening through said first wall whereby coolant flow around the peripheries of said passage defining walls also cools said component receiving wall.

8. In the cylinder head of claim 7, a plurality of cooling spines projecting upwardly from the coolant chamber surface of said first wall and disposed between adjacent passage defining walls to increase the cooling efliciency at said locations.

References Cited UNITED STATES PATENTS 1,526,744 2/1925 Eberle 123-4l.79 1,556,338 10/ 1925 Mangold 123-4179 1,845,521 2/1932 Ross 12341.77 2,000,979 5/1935 Parkhill et a1 123-4177 2,077,225 4/1937 Daiber l2341.77 2,120,344 6/ 1938 Zahodiakin 1234l.79

AL LAWRENCE SMITH, Primary Examiner. 

